The present invention relates to methods for raising commercial or farm animals, such as birds, fish and mammals, which improve the animals' behavioral characteristics, feeding habits and mortality rates. More particularly, the invention to relates to a method of raising precocial birds utilizing filial imprinting, environmental enrichment and music, and a method of raising farm animals by exposing them to toys.
Filial imprinting, the attachment of young birds to the first object they encounter, is a widely studied phenomenon. The attachment of precocial birds to an imprinting object may be expressed as physical contact, approach response, orienting movements, or reduction of stress behavior. Experiments with 10 day old chicks have suggested that the use of an imprinting stimulus or commonal feeding may have an effect on weight gain in young chicks when compared to chicks fed in isolation. Recent experiments have shown that large populations of heavy strain chicks can be attached to an imprinting stimulus, and the imprinting objects can then be used to move birds from a training area to a new location. In addition to facilitating movement, imprinted chicks spatially distributed themselves more equally in a new area around the imprinting objects. In this initial study, the imprinting objects provided recorded bird sounds to enhance the imprintability of the chicks.
The present inventors have newly observed that imprinted chicks appeared to be less fearful than controls. In addition, imprinted chicks appeared to feed more frequently.
Environmental enrichment involves the increase of stimulus value of the home environment by increasing its complexity. There is considerable evidence that environmental enrichment results in marked behavioral and physiological effects on mammals. In contrast to the many mammalian studies, very little is known about the effect of environmental enrichment on birds. In one study, however, it was found that environmental enrichment improved body weight gain, relative body weight gain and gain:food ratio in 9 day old broiler chicks.
Music has been associated with the treatment of human disease since ancient times, and its many physiological and psychological effects on humans is well known. Effects of music on animals, however, has not been well studied. Popular publications report that music can be used to increase milk production in dairy cows, and recent studies indicate that swine may also respond in a favorable manner. No significant influence of music on precocial birds has been previously demonstrated. In one study, meat type chicks were exposed to different kinds of continuous music, and it was stated that low level dinner music improved body gain weight and food:gain ratio very slightly, though the data was not statistically significant.
Until now, the use of filial imprinting, environmental enrichment and music in combination to improve behavioral characteristics, feeding habits and mortality rates in precocial birds has not been suggested or attempted. It has now been found experimentally, that this triple combination has a significant effect on these parameters.
Toys are objects which can be utilized by an animal for play. Play in animals has been described as "leaping; jumping; bucking or running when there is no obstacle to overcome, no enemy to fee, or object to obtain; sniffing; licking, pawing and manipulating familiar rather than novel objects; sex without coition; and, fighting in friendly rather than aggressive encounters which avoids injuring or routing the partner." (McFarland, 1981). According to McFarland, there are at least five categories of play activities:
1. Superfluous activity includes prancing, frisking, leaping, gambolling, etc., and has been in observed cattle, horses, sheep, goats and chicks.
2. Aimless exploration, manipulation and object play involves the use of novel stimuli and objects which typically elicit approach, touching, mouthing and other manipulations, providing the animal is not frightened.
3. Practice play is often seen in animals whose movement is still not perfected at birth, and involves the repetition and elaboration of newly acquired and chance actions.
4. Responses to the wrong object are often found in young animals, and comprise innate stereotyped movements to inappropriate objects.
5. Finally, social play is play between young animals and between the young and their parents. It has been suggested that social play may serve to establish dominance relationships, or to control aggression between group members.
Toys are the objects for animal play, and serve to stimulate other kinds of play or activity. Toys were developed and have been used for many years for pets (for cats, dogs, birds and aquarium fish). Farm animals, unlike pets and wild animals, however, remain in poor and monotonic environments for the majority of their lives without any objects or toys to stimulate their senses. Since it appears that all animals require a certain amount of play type activity, it would appear to be beneficial to farm animals to enhance or enrich their playing environment. If such an enrichment to their playing environment results in improved behavioral characteristics, feeding habits and mortality rates, for example, the derived economic benefit can be substantial, especially in a commercial farm environment where large numbers of animals are involved.